Protective treatment of fiber products



atented ct. 4,

TREADW'AY Eb. METHYL-0E AND ELBERT C. LATHIRGR-OF CHICAGO, ILLINOI'S, ASSIGIG'GRQ EQ GELGTEE GOFIEAIEY, G1 GEIC'AGO,

ILLINDIS, it GOBEGEATIUN 0F ltis, of course, well-known that termites causedamage, throughmany portions of the world but particularly in the tropical and subtropical portions thereof, by attacking and destroying wood used in construction. These insects in fact not only destroy wood but they will attack and destroy substantially any woody material, and among the materials which they attack are included wallboards, building boards, insulating boards, and the like made from wood fiber or from the fiber of various forms of vegetative growth. Not only do termites attack and destroy board-like materials composed of wood fiber and various vegetative fibers, but they J also attack substantially any product made u of fiber such as was mentioned, and in addition they attack and destroy pzzper products, cotton goods, leather, and the like.

It is the object of this invention to'provide a treatment of fibrous products, particularly but not only those in board form, which through being toxic or repellent will deter attacks by termites and thereby afford protection therefrom. Particularly there is contemplated an integral treatment, of the various'products, which is applied to the component fibers of fibrous material prior to its formation into the eventual products, whereb the treatment is efiective throughout the ody thereof. It is contem lated that this treatment may be appliedto su stantially any product subject to the attacks of termites, which product is manufactured in such manner that the treatment is applicable at some stage prior to the final formation of the product.

Specifically, the treatment for productionagainst damage by termites comprises the incorporation of a termite-repellent substance to the component elements which make up the final product, the application being made in the form of an emulsion or fluid suspension from which the termite-repellent material is precipitated on the elemental sub- Application filed Easy 29,

1980. Serial No. 457,5 39.

stances of the product prior to the final formation into the finished product.

Various termite-repellent or toxic chemicals are available, comprising compounds of chlorinated diphenyl compounds, and thelikc. These compounds may be emulsified or suspended and precipitated on the fiber from which the final product is formed, which procedure will be described specifically in connection with chlorinated naphthalene. The various compounds referred to in the following text are either insect-repellent or toxic to insects, or possibly have the eilect of being both toxic and repellent, and it is to be understood that reference hereafter to a substance as being insector termite-repellent is intended to have the meaning that the substance is insect-repellent and/or toxic, or that it is both repellent and toxic.

Specifically, by way of example, the objects of the invention are accomplished in connection with rendering a fiber board repellent to termites by precipitating upon the fibers thereof chlorinated naphthalene prior to the formation of the fibers into the finished board; like process may be applied, tor instance, to cotton prior to felting into a sheet of felt, to pulp prior to formation into a formed'article, and is further likewise applicable in manyother particular applications. While chlorinated naphthalene is specifically mentioned, the same method or" application of the termite-repellent substance may be followed in the application of various materials other than'chlorinated naphthalene, the only necessary characteristics of such material being that it may be emulsified or suitably suspended in a fluid and that the emulsion or suspension aiter being mixed with the fiber can It is, of course, understood that a size.

hard, waxy substance at ordinar 'tures. The waxy chloro-naphtha ene is softbe broken down to precipitate the repellent material upon the fiber.

Chlorinated na hthalene, it is to be understood, is obtaina le in different forms, depending chiefly the complexity of the combinations involved; that 1s, it may be an oily liquid comprising only mono-chloro-naphthalene and thence through a series of waxes of various properties which comprise in various proportions mixtures of mono-chloronaphthalene, di-chloro-naphthalene, tri-chloro-naphthalene, etc.

It appears that a chloro-naphthalene com prising substantially.49% chlorine and composed of probably, di-tri-, and probably higher chlorides of chloro-naphthalene is uite efficient in repelling attacks by termites,w 'ch form of chloro-naphthalene is a moderately temperaened by application of heat, and there is added stearic acid and otassium hydroxide, and the whole is emulsi ed with water in any appropriate manner, such as by the use of a colloid mill, and thus there is produced an emulsion comprising a dispersion of chloronaphthalene in water which may or may not be a true emulsion depending on the particle It is, of course, to be understood that the emulsification can be accomplished by the use of emulsifying agents other than the potassium stearateformed by the combination of the potassium hydroxide and steartc acid, and that theseparticular emulsifying agents are given only by way'of example, and

that the particular method of emulsification of the chloro-naphthalene is not essential to the invention in that any satisfactory emulsion may be used. Proportions which have been found satisfactory are 45 parts of chloro-naphthalene, 5 parts of stearlc acid, 1 part of potassium hydroxide, which materials are emulsified with 225 parts of water to produce a 20% emulsion of'chloro-naphthalene.

In treatin board-like material formed from wood fi r or vegetative fiber with the chloro-naphthalene emulsion prior to the formation of such fibrous material into board products, the emulsion diluted to the proper sizing chemicals the action of the rosin and ndd alum, particularly of the alum, being to cause a demulsification or recipitation of. the suspended chloro-napht alene which is deposited uponthe'fibers. K

Due to the fact that the aluminum of the alum used in sizing combines with the stearic nsion with acid ofthe emulsion to form an aluminum stearate which is not an emulsification agent, and due to the strong coa lating action of aluminum salts because 0 the high electric charge of the aluminum i011 or aluminum hyployed to cause breaking down of the emulsion, it is to be understood that substantially any other chemical which will combine with the stearic acid' or other emulsifying agent to form-a compound which is not anemulsifying agent, otherwise such a substance as will break down the emulsifying agent, will satisf the conditions necessary to cause the preclpitation. The fiber on which the chloronaphthalene hasbeen precipitated from this emulsion is then formed into its finished form, for instance, on a board-forming machine wherein the fiber is sheeted and the white water or water in which it has been suspended is drained away. The formed sheet is properl dried to produce the finished product w ich will have incorporated'therein, integrally throughout, the chloro-na'ph-- thalene which was in ;the emulsion.

Attention is directed to the fact that there is a certain amount of loss due to incomplete precipitation of the chloro-naphthalene on the fiber; that is, in general there willbe a certain amount which is not demulsified, and therefore a loss of around. 20% can be expected in the white water if the fiber is formed into a board ona wet board machine. naphthalene is volatile at temperatures'of 300-400 F., and therefore in drying a fiber board integrally treated with chloro-naphthalene-the temperature of drying should be held as low as practical to preventexcessive vaporization losses during the drying action and, tb'take care of the losses which have just been mentioned, it is essential that the original amount of chloro-nap'hthalene emulsion be increased proportionately in order that the final product may have the desire amount of treatment.

It is to be understood that, while the application of this integral treatment has been specifically discussed in connection with the treatment of the fiber board product, the principles which are illustrated by such treatment are generally applicable as has been heretofore stated, and that it is not the intention to limit the invention in accordance with the specificillustration of a particular Chlorofibrous product wherein the fiber from embodiment of the invention given.

Whatis claimed is 1. The method of integrally treating a as has been which the product is formed has added thereto while in water suspension emulsified chloro-naphthalene with the subsequent addition of a demulsifying agent, whereby the ohlorosnaphthalene is precipitatedflupon the fibers.

2. The method of integrally applying to a sheeted fibrous product a termite repellent compound wherein there is added to the fiber, prior to formation, an emulsion of chlorohalogen group, wherein a dilute emulsion of the insecticide is added to a dilute suspension of fibrous material, after which the emulsion is broken, whereby the insecticide is thrown out on the suspended fiber, which suspended fiber together with the insecticide is subsequently felted on the screen of a machine of the general type used in paper making.

In testimony whereo we ailix our signatures. TREADWAY B. MUNROE.

ELBERT C. LATHROP.

naphthalene with the subsequentaddition of stance is emulsified and added to pulped fibrous material, to which mixture is'added a substance breaking down the emulsion, whereby the insect-repellent substancemay precipitate on the fibrous material, resulting in a. product which, on sheeting, has distributed therethrough the insect-repellent substance. I I

5. The method of introducing into a felted fiber product an insect-repellent substance wherein the insect-repellent substance in liquid suspension,-is added to a fiber suspension to which mixture isadded the substance causing flocculation, whereby the insect-repellent substance is precipitated on the fibrous 1 material, resulting in. a productwhich on sheeting has distributed there-v through the insect-repellent substance.

6. The method of introducing into a felted fibrous product a compound in which hydro gen in the nucleus of aromatic ringsystem phenols has been replaced by a member of the halogen group, wherein the compound in aqueous suspension is added to ulped fi-' brous material, there being sugsequently added a flocculating-agent, depositing the compound upon the pulp, whereby-the resulting product has on formation the insectrepellent compound distributed therethrough.

7. The method of introducing into a felted fibrous product, in the course of its manu facture an insecticide in which hydrogenin the nucleus of an aromatic ring system hydrocarbon has Men replaced by a member of the lot 

